Quick Question About Adding Border and Inserting Photo (Basic)

Hi all,

I am sure these questions will be easy for someone to answer, I just couldn't find a clear answer through a basic online search.

1. I wanted to add a simple white border to my photo. The first method I tried was by making a canvas that was a white square that was 4272 x 4272 px. and then dragging and dropping my photo into this canvas. The original photo size is 3872 x 2592 px. However, when I did that, the photo resized automatically to fit the canvas. I have seen other videos where the photo is dropped into a larger canvas and it automatically stays the same size and then there is a border formed by the original white canvas. Is there any way to achieve this so that this method works.

2. I am curious if the size of the canvas in pixels affects the image quality in any way. In other words, does the quality of the canvas effect the quality of the image that is within it?

3. How do I make a template so that I don't have to recreate these borders every time?

Matt